UAN is a solution of urea, ammonium nitrate
and water that is used as a fertilizer. Both
fast acting and long lasting nourishment is
provided by three forms of nitrogen. These
are ammonic nitrogen, nitrate and the water
soluble organic nitrogen in urea.

Typically, UAN is analyzed to determine the
concentrations of ammonium nitrate, urea
and total nitrogen. A common grade of these
fertilizer solutions is UAN 32, which is 45%
ammonium nitrate, 35% urea and 20% water
resulting in a total nitrogen concentration of
32%.